Abstract
Background: Long non-coding RNAs play an important role in breast cancer. Even with adjuvant hormone therapy, patients with estrogen receptor positive breast cancer can present with recurrences and distant metastases. We investigated whether the expression of a novel long non-coding RNA LINC00309 can predict the outcome of breast cancer, especially for hormone-receptor positive patients. Methods: This retrospective study collected 290 breast cancer patients including 161 patients with hormone-positive. qPCR was performed to detect the expression of LINC00309. Kaplan-Meier and Cox risk proportion model were applied to disclose the function of LINC00309 for breast cancer prognosis. Results: LINC00309 high expression was an independent predictor for worse disease-free survival (HR = 2.127; 95% CI 1.074-4.212; p = 0.030) and associated with a shorter disease-free survival (p = 0.027), especially in hormone-positive breast cancer patients (p = 0.001). Also LINC00309 high expression was associated with a shorter disease-free survival both in selective estrogen receptor modulator related hormone therapy (p = 0.025) and aromatase inhibitors related hormone therapy (p = 0.048). Moreover, LINC00309 was an independent predictor of worse disease-free survival in hormone-receptor positive breast cancer patients on univariate (HR = 4.505; 95% CI 1.722-11.785; p = 0.002) and multivariate (HR = 4.159; 95% CI 1.537-11.251; p = 0.005) analyses. Conclusion: In breast cancer, Linc00309 is significantly associated with poor prognosis and may represent a new marker of prognosis.